The invention relates generally to video processing, and in particular, to padding a video image.
With the development of digital video signal recording technology, it is expected that digital video signal reproduction devices will have improved image quality. Typical encoding schemes, such as those developed by MPEG (Motion Picture Coding Experts Group), generally operate to highly compress video information to facilitate its transmission over channels of very limited bandwidth. According to systems that operate using the MPEG standards, video and audio data are compressed and recorded on a storage device in a time-division-multiplexed format.
The MPEG-4 video coding standard supports arbitrarily shaped video objects in addition to the conventional frame-based functionality in MPEG-1 and MPEG-2. Thus, in MPEG-4, the video input is no longer considered as a rectangular region.
However, the MPEG-4 video coding scheme processes the successive images of a video object plane (VOP) sequence in a block-based manner (e.g., using motion estimation, motion compensation, discrete cosine transform (DCT), or inverse discrete cosine transform (IDCT)). Therefore, before motion estimation, motion compensation, or DCT can be performed, the non-object pixels of contour macroblocks, which contain the shape edge of an object, must be filled.